Sorry for the delay, I've been moving house/jobs and have been either busy or without internet!

I'm not sure what you mean.

According to Zombaio Features, your customers can pay in a lot of different currencies and Zombaio converts the currency used to pay to the currency that your account is in. (Much the same as PayPal does unless you put it in Multi Currency mode)

We offer client account currencies EUR and USD, this means that your account balance is held in one of those currencies. If your members choose to pay in another currency, the amount will be exchanged to your base currency.

We offer the following currencies to your members: EUR,USD,SEK,JPY,GBP,AUD,CAD,CNY,HKD,KRW,BGN,BRL,CZK,DKK,
EEK,HUF,LTL,LVL,MXN,PLN,RON,SKK,CHF,ISK,NOK,HRK,RUB,TRY,IDR,MYR,NZD,PHP,SGD,THB,ZAR

So there is no need to have two Zombaio Accounts in use.
Your customers should be able to select the currency to use on the form/at payment. Not that it matters as if the customer pays in EUR and your account is in USD, their credit/debit card will handle the currency conversion and the same conversely.

I've just had a poke about in ZOA, and my account is in USD, and I can find a easy way to flip the core currency, on a site, or pricing structure basis.